Reading and Making Picture Graphs (Pictographs) - First Grade Mathematics

Have you ever heard the saying: "A picture is worth a thousand words"? In mathematics, pictures can also tell a wonderful numerical story! A picture graph (also called a pictograph) is a colorful chart that uses pictures or symbols to show data. Instead of looking at a plain list of numbers, a picture graph lets your eyes see quantities instantly: taller stacks of pictures mean larger amounts, and shorter stacks mean smaller amounts. In this chapter, you will master reading picture graphs with a scale of 1, understand the importance of the key, and create your own graphs.

The Anatomy of a Picture Graph

A picture graph has four essential components that make it easy to understand:

The Four Parts of a Picture Graph:

1. TITLE: Tells what the graph is about.
2. CATEGORIES: The different groups being compared.
3. PICTURE SYMBOLS: The symbols representing the data items.
4. KEY: Explains what each picture symbol stands for!

Favorite Fruits Picture Graph:

Title: Our Favorite Fruits

Apples   |  (*)  (*)  (*)  (*)  (*)
Bananas  |  (*)  (*)  (*)  (*)  (*)  (*)  (*)
Oranges  |  (*)  (*)  (*)

Key: Each (*) = 1 vote

The Key Is the Secret Decoder!

Look at the bottom of the graph: Key: Each (*) = 1 vote. The key is the most critical part of any picture graph! It tells you how much each symbol is worth. In first grade, each picture stands for exactly 1 ITEM (a single-unit scale).

Reading Data from a Picture Graph

Looking at our Favorite Fruits graph above: Row 1 (Apples): Count the symbols: 1, 2, 3, 4, 5. Five students chose apples! Row 2 (Bananas): Count the symbols: 1, 2, 3, 4, 5, 6, 7. Seven students chose bananas! Row 3 (Oranges): Count the symbols: 1, 2, 3. Three students chose oranges!

Comparing Rows Visually

Even before you count the symbols, your eyes can see that the Bananas row stretches out the furthest! Bananas is the most popular fruit. The Oranges row is the shortest, meaning oranges is the least popular fruit.

Vertical vs. Horizontal Picture Graphs

Picture graphs can be drawn in two different directions:

Horizontal Graph (Rows):
Apples:  (*) (*) (*) (*) (*)
Bananas: (*) (*) (*) (*) (*) (*) (*)

Vertical Graph (Towers):
           Bananas
              *
              *
    Apples    *
      *       *
      *       *
      *       *
      *       *
   +-------+-------+

Both Tell the Same Story!

Whether the pictures stretch across in horizontal rows or climb up into vertical towers, the data is identical.

Practice Exercises

Exercise 1: Name the four main parts of a picture graph.

Exercise 2: Why is the "key" such an important part of a picture graph?

Exercise 3: Look at a picture graph showing Books Read. Maya has 6 book symbols next to her name. The key says: Each picture = 1 book. How many books did Maya read?

Exercise 4: In the Favorite Fruits graph from this chapter, how many more students chose bananas than oranges? Show the subtraction equation.

Solutions and Explanations

Solution to Exercise 1: The four main parts of a picture graph are the Title, the Categories, the Picture Symbols, and the Key.

Solution to Exercise 2: The key is important because it acts as the decoder for the graph; it tells the reader exactly how many items or votes each picture symbol represents.

Solution to Exercise 3: Maya read 6 books (6 symbols x 1 book each = 6 books).

Solution to Exercise 4: Bananas had 7 votes and oranges had 3 votes. The subtraction equation is 7 - 3 = 4. 4 more students chose bananas than oranges.